{"id":200376,"date":"2025-05-06T09:22:57","date_gmt":"2025-05-06T01:22:57","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200376\/"},"modified":"2025-05-06T09:22:57","modified_gmt":"2025-05-06T01:22:57","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-mysql-distinct-%e5%8e%bb%e9%87%8d%e5%b9%b6%e5%8c%ba%e5%88%86%e5%a2%83%e5%86%85%e5%a4%96%e5%9f%9f%e5%90%8d%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200376\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528 MySQL DISTINCT \u53bb\u91cd\u5e76\u533a\u5206\u5883\u5185\u5916\u57df\u540d\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u4f7f\u7528 MySQL DISTINCT \u53bb\u91cd\u5e76\u533a\u5206\u5883\u5185\u5916\u57df\u540d\uff1f<\/h1>\n<p>\u7f16\u7a0b\u5e76\u4e0d\u662f\u4e00\u4e2a\u673a\u68b0\u6027\u7684\u5de5\u4f5c\uff0c\u800c\u662f\u9700\u8981\u6709\u601d\u8003\uff0c\u6709\u521b\u65b0\u7684\u5de5\u4f5c\uff0c\u8bed\u6cd5\u662f\u56fa\u5b9a\u7684\uff0c\u4f46\u89e3\u51b3\u95ee\u9898\u7684\u601d\u8def\u5219\u662f\u4f9d\u9760\u4eba\u7684\u601d\u7ef4\uff0c\u8fd9\u5c31\u9700\u8981\u6211\u4eec\u575a\u6301\u5b66\u4e60\u548c\u66f4\u65b0\u81ea\u5df1\u7684\u77e5\u8bc6\u3002\u4eca\u5929\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6574\u7406\u5206\u4eab\u300a\u5982\u4f55\u4f7f\u7528 MySQL DISTINCT \u53bb\u91cd\u5e76\u533a\u5206\u5883\u5185\u5916\u57df\u540d\uff1f\u300b\uff0c\u6587\u7ae0\u8bb2\u89e3\u7684\u77e5\u8bc6\u70b9\u4e3b\u8981\u5305\u62ec\uff0c\u5982\u679c\u4f60\u5bf9\u6570\u636e\u5e93\u65b9\u9762\u7684\u77e5\u8bc6\u70b9\u611f\u5174\u8da3\uff0c\u5c31\u4e0d\u8981\u9519\u8fc7\u4e3b\u673a\u5b9d\u8d1d\uff0c\u5728\u8fd9\u53ef\u4ee5\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u52a9\u529b\u5f00\u53d1\u80fd\u529b\u7684\u63d0\u5347\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241103\/173062534767273f43e47e6.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>mysql \u6309\u6761\u4ef6\u8fdb\u884c distinct \u53bb\u91cd<\/strong><\/p>\n<p>\u4e3a\u4e86\u89e3\u51b3\u6309\u5b57\u6bb5 loc \u5bf9 domain \u8fdb\u884c\u53bb\u91cd\u7684\u95ee\u9898\uff0c\u9700\u8981\u8003\u8651\u4ee5\u4e0b\u65b9\u6cd5\uff1a<\/p>\n<p><strong>\u4f7f\u7528 union all<\/strong><\/p>\n<pre>select distinct domain from url where loc = \"\u5883\u5916\" union all\n(select distinct domain from url where loc != \"\u5883\u5916\")<\/pre>\n<p>\u6b64\u65b9\u6cd5\u5c06\u67e5\u8be2\u51fa\u6240\u6709\u5883\u5916\u57df\u540d\u548c\u975e\u5883\u5916\u57df\u540d\uff0c\u5e76\u5c06\u5b83\u4eec\u5408\u5e76\u4e3a\u4e00\u4e2a\u7ed3\u679c\u96c6\u3002<\/p>\n<p><strong>\u6309\u662f\u5426\u5883\u5916\u4eba\u4e3a\u589e\u52a0\u5b57\u6bb5<\/strong><\/p>\n<p>\u5982\u679c\u65e0\u6cd5\u5c06\u5883\u5185\u5916\u4fe1\u606f\u653e\u5165\u5355\u72ec\u7684\u5b57\u6bb5\u4e2d\uff0c\u5219\u53ef\u4ee5\u8003\u8651\u4eba\u4e3a\u589e\u52a0\u4e00\u4e2a\u5b57\u6bb5 is_out \u6765\u8868\u793a\u662f\u5426\u5883\u5916\uff1a<\/p>\n<pre>select distinct domain, is_out from url<\/pre>\n<p>\u5982\u679c\u786e\u5b9a\u53ea\u6709 loc=&#8221;\u5883\u5916&#8221; \u4e3a\u5883\u5916\uff0c\u5219\u53ef\u4ee5\u6309\u7167\u5982\u4e0b\u7f16\u5199\u67e5\u8be2\u8bed\u53e5\uff1a<\/p>\n<pre>SELECT DISTINCT domain FROM url WHERE loc = \"\u5883\u5916\"<\/pre>\n<p>\u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300a\u5982\u4f55\u4f7f\u7528 MySQL DISTINCT \u53bb\u91cd\u5e76\u533a\u5206\u5883\u5185\u5916\u57df\u540d\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u4f7f\u7528 MySQL DISTI&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200376","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200376","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200376"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200376\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200376"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200376"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}